It's hard to pick an outright winner, but one thing is clear: Health care for your Windows-based PC is getting easier, cheaper and more comprehensive.

"Microsoft's official entry into the consumer security protection market will dampen prices," Gartner analyst Arabella Hallawell said. The Redmond, Wash.-based software giant is poised to take a big chunk of that niche, she said. "Existing vendors must converge their offerings to warrant premium pricing and survive."

The introduction of OneCare is the starting gun for heightened competition for consumers' security dollars, with Microsoft taking on incumbents Symantec and McAfee. There's a lot at stake. Last year, the worldwide market for consumer antivirus software reached $1.95 billion, up 17 percent year-over-year, according to research from Gartner. Symantec dominated the space, taking a 70 percent piece of the pie.

Microsoft isn't just a newcomer to consumer security; it's also taking a different tack. The OneCare software and service package aims to be comprehensive, whereas Symantec and McAfee have traditionally charged for additional features. OneCare includes the security basics--antivirus, anti-spyware and firewall--found in the products sold by its rivals, but adds backup features and tune-up tools for Windows systems. It's being touted by Microsoft as "a pit crew for your PC."

"We believe we're creating a new category," Dennis Bonsall, Microsoft's director of product management for OneCare, said in an interview last week. "It is not about security anymore, but it is about holistic PC care."

Symantec and McAfee have both announced that they are preparing integrated packages to go up against OneCare. The planned releases will incorporate components of their current security, PC optimization and backup products, the companies have said. So far, however, they have shown only product plans, not actual software.

The lack of a rival product on the market, or even available in a test version, doesn't bode well for the traditional security players. "Microsoft has the first-mover advantage by having a managed consumer security service ready to go first," Hallawell said.

There are some limitations to OneCare in early comparisons of features. For example, Symantec promises to deliver online backup capabilities in Norton 360, which will let people store their critical data on a Symantec server. Right now, Microsoft does not offer that feature in OneCare, where people can only back up to external hard drives, CDs or DVDs.

Additionally, OneCare lacks spam-filtering capabilities and doesn't offer protection against information-stealing Web sites used in phishing scams. Those features will be part of Symantec and McAfee's PC care suites, the companies have said. Microsoft, meanwhile, offers a phishing shield in its toolbars in Windows Live and in the MSN Search Web browser.

"Symantec will likely have a managed service with more bells and whistles," Hallawell suggested.

But the incumbents will have to cut their prices, as they face off with Microsoft and one another, analysts said. Symantec and McAfee have not announced pricing for their new products yet, but Microsoft will undercut them, no matter what, Forrester Research analyst Natalie Lambert said.

"Microsoft is going to win on price," she said. And with consumers being very cost-conscious, that's going to be half the battle, Lambert said.

OneCare costs $49.95 per year for use on up to three PCs that run Windows XP with Service Pack 2. That's less than Symantec and McAfee charge for three-user editions of their existing security suites--$119.99 and $129.99, respectively. However, those are full prices for the packages, which don't have as wide a range of tools as the upcoming products and which are often heavily rebated.